Starburst polyp encrusting problem

[kwan]

The purple red encrusting of my starburst polyps seems to be thining out. This encrusting used to be pretty thick and wraps round a piece of LR. But in recent weeks, it is thinning out and there are a few holes appearing through it, so you can see the rock surface underneath it. Some of the polyps on this thinned out encrusting also seems to have died.

What is the problem here? However, the encrusting is still growing and spreading across other part of the LR.

[Jason]

what kind of flow are they in? i have some crazy ones that grow about 1.5" a month and they do that all the time. If they are in a strong current, they get those little holes in the part that encrust, but they still grow.

[kwan]

It is in medium water flow. The only think that comes to my mind is this part of encrust is often occupied by my arrow crab, who just hangs off it.

[Jason]

hmmm that's weird. I guess I wouldn't worry about it if I were you. GSP are nearly impossible to kill. Just let them hang out for a little while and see what happens to them.

[MarineFlake]

Proper alk/ca/mg and strontium levels? Check Ammonia/Nitrites and Nitrates as well as look for elevated po4? Essentially, if its thinning something isn't right. I suggest you get a good snap shot of water chemistry/temp/SG and make sure there is nothing 'picking' at it. I had the same experience with xenia. It once grew like a weed (I removed a cup/month) in my tank. Then, while not monitoring alk, it started to wither. A few adjustments and ta-da, good as new. Suffice to say as tough as some of these corals are, if they do show signs of problems its time to assess the mess ; )

GL!

[kwan]

My parameters are good; pH=8.1, kH=9dKH, CA=400, mg=1200, NO2=0, NO3=10, PO4=.01, SG=1.024, and temp=82F I don't have a test kit for strontium though.

I am having similar problems with my Xenia as well. So something is definitely not right.

I also notice parts of my coraline algea are turning white, a chalky white. I don't know what might be causing it, especially my CA/mg/alk is balanced.